TYK2 notes

Deep research providers unavailable in this environment (falcon/perplexity-lite failed); research done
from cached publications and the UniProt record.

• Non-receptor PTK; no TM domain PMID:2216457.
• Binds and phosphorylates IFNAR1 PMID:7526154; structure of FERM-SH2 with IFNAR1 box2 PMID:24704786.
• Phosphorylates STAT1 Tyr701 PMID:7657660; catalytic activity required for STAT3/IFNAR1 phosphorylation
  PMID:10542297.
• Pathways: type I IFN PMID:1386289, IL-10 PMID:7543512, IL-12/IL-23 PMID:7528775.
• Unverified: IFN-gamma (PMID:8232552 abstract assigns it to JAK1/JAK2), IL-5 (PMID:7888666, PMID:1495999
  abstracts mention only JAK2/IL5RA) -> UNDECIDED.

Localization conclusion

Intracellular: peripheral protein on the cytoplasmic side of the plasma membrane, docked on cytokine
receptor ICDs PMID:24704786, plus a cytosolic pool. Not exposed at the cell surface.
Generic plasma membrane / membrane terms modified to GO:0031234.